蟒蛇
由于我无法将dijkstra代码压缩到数百个字节,因此这是我的非高尔夫版本。
import sys, heapq, time
# dijkstra algorithm from
# http://code.activestate.com/recipes/119466-dijkstras-algorithm-for-shortest-paths/
def dijkstra(G, start, end):
def flatten(L):
while len(L) > 0:
yield L[0]
L = L[1]
q = [(0, start, ())]
visited = set()
while True:
(cost, v1, path) = heapq.heappop(q)
if v1 not in visited:
visited.add(v1)
if v1 == end:
return list(flatten(path))[::-1] + [v1]
path = (v1, path)
for (v2, cost2) in G[v1].iteritems():
if v2 not in visited:
heapq.heappush(q, (cost + cost2, v2, path))
nodes = tuple(sys.argv[1:])
print "Generating connections,",
current_time = time.time()
words = set(x for x in open("websters-dictionary", "rb").read().lower().split() if 3 <= len(x) <= max(5, *[len(l)+1 for l in nodes]))
print len(words), "nodes found"
def error():
sys.exit("Unreachable Route between '%s' and '%s'" % nodes)
if not all(node in words for node in nodes):
error()
# following codes are modified version of
# http://norvig.com/spell-correct.html
alphabet = 'abcdefghijklmnopqrstuvwxyz'
def edits(word):
splits = [(word[:i], word[i:]) for i in range(len(word) + 1)]
deletes = [a + b[1:] for a, b in splits if b]
replaces = [a + c + b[1:] for a, b in splits for c in alphabet if b]
prepends = [c+word for c in alphabet]
appends = [word+c for c in alphabet]
return words & set(deletes + replaces + prepends + appends)
# Generate connections between nodes to pass to dijkstra algorithm
G = dict((x, dict((y, 1) for y in edits(x))) for x in words)
print "All connections generated, %0.2fs taken" % (time.time() - current_time)
current_time = time.time()
try:
route = dijkstra(G, *nodes)
print '\n'.join(route)
print "%d hops, %0.2fs taken to search shortest path between '%s' & '%s'" % (len(route), time.time() - current_time, nodes[0], nodes[1])
except IndexError:
error()
测验
$ python codegolf-693.py post shot
Generating connections, 15930 nodes found
All connections generated, 2.09s taken
post
host
hot
shot
4 hops, 0.04s taken to search shortest path between 'post' & 'shot'
$ python codegolf-693.py zink silicon
Generating connections, 86565 nodes found
All connections generated, 13.91s taken
zink
pink
pank
pani
panic
pinic
sinic
sinico
silico
silicon
10 hops, 0.75s taken to search shortest path between 'zink' & 'silicon'
添加了user300的测试
$ python codegolf-693.py vas arm
Generating connections, 15930 nodes found
All connections generated, 2.06s taken
vas
bas
bam
aam
arm
5 hops, 0.07s taken to search shortest path between 'vas' & 'arm'
$ python codegolf-693.py oxy pom
Generating connections, 15930 nodes found
All connections generated, 2.05s taken
oxy
poxy
pox
pom
4 hops, 0.01s taken to search shortest path between 'oxy' & 'pom'
$ python codegolf-693.py regatta gyrally
Generating connections, 86565 nodes found
All connections generated, 13.95s taken
Unreachable Route between 'regatta' and 'gyrally'
多一点
$ python codegolf-693.py gap shrend
Generating connections, 56783 nodes found
All connections generated, 8.16s taken
gap
rap
crap
craw
crew
screw
shrew
shrewd
shrend
9 hops, 0.67s taken to search shortest path between 'gap' & 'shrend'
$ python codegolf-693.py guester overturn
Generating connections, 118828 nodes found
All connections generated, 19.63s taken
guester
guesten
gesten
geste
gest
gast
east
ease
erse
verse
verset
overset
oversee
overseed
oversend
oversand
overhand
overhard
overcard
overcare
overtare
overture
overturn
23 hops, 0.82s taken to search shortest path between 'guester' & 'overturn'